"The Naturals Series" is a young adult thriller book series written by Jennifer Lynn Barnes. It follows a group of teenagers with special abilities, such as profiling and deception detection, who are recruited by the FBI to help solve cold cases. The main character, Cassie Hobbes, has a unique talent for reading people, which plays a crucial role in their investigations. The series consists of four main books: "The Naturals," "Killer Instinct," "All In," and "Bad Blood." Each installment delves deeper into the characters' backgrounds and the challenges they face, blending suspense, mystery, and psychological elements to engage readers.